The role of PPR proteins in posttranscriptional regulation of organelle components in plants.

Pentatricopeptide repeat (PPR) proteins constitute one of the largest protein families in land plants. They are sequence-specific RNA-binding proteins and play key roles in posttranscriptional processes within organelles. Their combined actions have profound effects on chloroplast photosynthetic electron transport chain and mitochondrial respiratory chain, affecting photosynthesis and respiration respectively, and ultimately on yield, fertility, and grain quality.